Many people prefer the use of gaslights for illumination in exterior post lamps, entrance lights and street lamps because of their aesthetic appearance and because they create a street environment more typical of an earlier period of time. Gaslights are particularly preferred in portions of cities in which the architectural characteristics and ambiance of a particular period in history are desired to be maintained. However, gaslights have certain drawbacks, because they require the installation and maintenance of a supply of gas, which is not always practical, and because they cannot always be readily turned on and off. Also, the cost of installation and maintenance of a gaslight can be very high. For these reasons and because of the ready and cheap availability of electricity as a power source, electric lamps are commonly used in a manner to imitate gaslights. In the past, incandescent lamps have been employed in simulated gaslights. Examples of incandescent lamps used to simulate gaslights are found in U.S. Pat. Nos. 3,148,835; 4,577,265; and 4,616,299. However, such incandescent lamps have not proven to be satisfactory as a substitute for gaslights because even the best lamps do not closely resemble a gaslight either in intensity or in color. Furthermore, in some such incandescent lamps, the outline of the lamp or filament is visible.
Because of the increasing cost of electric energy, more energy efficient lamp types are often substituted for incandescent lamps. The most commonly used substitutes are fluorescent and high intensity discharge lamps. Both of such lamps have high luminous efficacies. One known type of compact fluorescent lamp includes two longitudinally extending leg members which are joined together by a transversely extending envelope portion. One example of such a commercially available lamp is the "twin-tube" fluorescent lamp manufactured by GTE Sylvania in Danvers, Mass., while another example of a commercially available lamp is the lamp sold as part of the MOD-U-LINE system by General Electric of Nela Park, Cleveland, Ohio. Even using fluorescent lamps, it is readily apparent on close observation that a light source is an electric lamp, as opposed to a gaslight. With some fluorescent lamps, the light output is non-uniform and the outline or silhouette of the bulb is visible. The color and intensity of the lamp also is distinguishable from that of a genuine gaslight. In lighting applications where the lamp envelope is clearly exposed, the light bears little resemblance to a gaslight. Examples of fluorescent lamps used for simulating gaslights are found in U.S. application Ser. Nos. 918,435; 918,444; and 918,459.
It is, therefore, an object of the present invention to provide an electric lamp which closely simulates the appearance of a gaslight.
It is another object of the present invention to provide a more energy efficient, fluorescent lamp which closely simulates the appearance of a gaslight.
It is still another of the present invention to provide an electric lamp assembly which generates light having generally the same color and intensity as light coming from a gaslight.
It is still another further object of the present invention to provide an electric lamp which simulates a gaslight and which can be installed in most conventional incandescent light fixtures.